Case: Gutteshield Systems Australia Pty Ltd v LBI Holdings Pty Limited NSWSC 735
Much of this case is outside of my expertise because it deals with rules regarding civil court procedure. But it's another indication of the problems that result when parties don't agree upfront on what the invention is and who owns it, including any improvements.
There is a tendency amongst practitioners to have their clients sign a Deed of Assignment that identifies an invention by its title. As far as I am concerned, such practice is dangerous and should be avoided. A proper Deed of Assignment should at least define the invention in an Annexure and can even include drawings. The agreement should also, where possible, set out what should happen with developments and improvements. For example, there could be supplementary agreements drawn up as improvements to inventions are developed.
Managing the ownership of IP should be regarded as a dynamic task and one that must be reviewed and audited on a regular basis. Otherwise the parties could look forward to five years in the court system, as has happened in this case.